Quantum mechanics, a branch of Physics that study the micro cosmos, has a fundamental principle known as “Uncertainty Principle”. This principle, discovered by Heisenberg, establishes the physical impossibility of knowing (or measuring), simultaneously, the position and speed of a particle with a precision larger than a given constant [1]. This imprecision is considered to be a fundamental law in quantum mechanics, and such uncertainty does not depend on any technology, it is considered to be an attribute of the universe.

Since the advent of the “Expanded Science” [2], we know it is impossible to refute a theory as Popper thought. Everything indicated a more comprehensive and less uncertain view of the universe. Such uncertainty must comprehend our observations. Based on these conclusions, I shall propose a principle, which I called “Philosophical Uncertainty Principle”, or PUP.

The PUP establishes that:

“It is impossible to know if some observation, measure or perception corresponds in fact to reality”.

We can take reality as something that exists regardless of any interpretation, processing or imagination.

Many should probably have already had this idea, but have not formalized it yet because, since the advent of the concept of “Solipsism” [3], we know it is impossible to prove that anything can be in fact reality. And worse than that, even the Solipsism itself can be an illusion, since the “I” that realizes can also be unreal, as shown in “The Existence Theorem (I think, therefore it exists)” [4]. That is, it is possible that the “being” itself that observes thinks and feels, does not exist in another level of interpretation.

Besides that, and more important, even if we assumed our reality as real, that is, it exists regardless of any interpretation of a higher level as it is supposed by science, we would still have problems: even so we could not take any observation as real. In order to understand that, we must steal the “shoe box” example from the essay “Expanded Science” [2]:

Suppose we are walking on the street and we observe a shoe box with a brick inside. Can we infer from our observation that what we saw was a shoe box with a brick inside? Unfortunately the answer is no. In principle, one of the following situations can occur – from infinite possible ones – when we observe a brick that is not a brick: It was the volume of a radio imitating a brick.

It was something similar to a brick, but not a brick.

A momentary cerebral short-circuit made you imagine a brick inside an empty box.

A new alpha-waves gun was tested on you so you could imagine the brick.

Someone created a holographic image of the brick so you would think it was real.

Etc

Such mistakes, although improbable, can happen in any level of observation, be it scientific or not. And that justifies PUP as a fundamental philosophic-scientific principle about the limit of knowledge.